Decrementing the iterator here could be wrong if the worklist is empty after the "erase".

Thanks to Ji Young Park for the patch!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56316 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 4 deletions

diff --git a/lib/Transforms/Scalar/DCE.cpp b/lib/Transforms/Scalar/DCE.cpp
index cb78207d76..fb9a0e04fd 100644
--- a/lib/Transforms/Scalar/DCE.cpp
+++ b/lib/Transforms/Scalar/DCE.cpp
@@ -111,11 +111,12 @@ bool DCE::runOnFunction(Function &F) {
 
       // Remove the instruction from the worklist if it still exists in it.
       for (std::vector<Instruction*>::iterator WI = WorkList.begin();
-           WI != WorkList.end(); ++WI)
-        if (*WI == I) {
+           WI != WorkList.end(); ) {
+        if (*WI == I)
           WI = WorkList.erase(WI);
-          --WI;
-        }
+        else
+          ++WI;
+      }
 
       MadeChange = true;
       ++DCEEliminated;